An Improved Convex Combination Decorrelation Proportional Adaptive Echo Cancellation Method

Abstract

An improved convex combination decorrelation proportionate self-adaption echo cancellation method comprises the steps that first, far-end signal filtering is carried out, the input vector X(n) of a convex combination self-adaption echo cancellation filter is formed by the discrete value of a far-end signal, and after filtering is carried out on the input vector, a large-step-length filtering value y1(n) and a small-step-length filtering value y2(n) are obtained; second, decorrelation operation is carried out on the input vector X(n), the result of decorrelation operation serves as the weight coefficient updating direction vector Z(n) of the convex combination self-adaption echo cancellation filter; third, convex combination is carried out, the large-step-length filtering value y1(n) and the small-step-length filtering value y2(n) are subjected to convex combination through weight lambda (n), and a combination filter value y(n) is obtained; fourth, echo cancellation is carried out, the combination filter value y(n) is subtracted from a near-end signal d(n) with an echo, and the subtracted near-end signal d(n) is fed back to the far end; fifth, a filter tap weight coefficient is updated; sixth, the weight of the filter is updated; seventh, the weight of the filter is limited; eighth, n is made to be equal to n+1, the first step to the seventh step are repeated till a conversation is over. According to the method, a high rate of convergence can be obtained, the steady state error can be small, and a good anti-jamming capability is achieved.

Description

technical field [0001] The invention belongs to the technical field of adaptive echo cancellation for telephone communication. Background technique [0002] When using wired, wireless, network and other communication devices, users will occasionally hear their own voice at the receiving end. This phenomenon is called echo phenomenon. For example, when a multi-person network audio conference is held or a user uses the hands-free function of a communication device, an acoustic echo is often generated. The principle of the generation is that the voice signal of the caller is picked up by the microphone, transmitted to the near-end and then amplified by the speaker for output. An echo is generated in the near-end room, and the echo signal is picked up by the near-end microphone and sent back to the far-end output, so that the caller can hear his own voice. Under extreme conditions, when the echo signal gain is too large to form positive feedback, it will cause harsh howling, ma...

AI Technical Summary

Problems solved by technology

However, the algorithm still exhibits the defect of slow convergence when dealing with related signals (such as speech signals)

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